Pantaleoni, Maffeo (mäf-fĕˈō päntälāôˈnē) [key], 1857–1924, Italian economist and politician. He was finance minister in Gabriele D'Annunzio's government at Fiume (1919), one of the first senators named by Benito Mussolini, and a delegate (1923) to the League of Nations. In Pure Economics (1889, tr. 1898, repr. 1957), Pantaleoni made a distinguished contribution to the theory of marginal utility. He also did notable work in statistics and finance.